[rfrey]

In many places, traffic would not function if drivers did not e.g. make space for other drivers to change lanes. It's an extraordinary claim to say such behaviour is bad practice (or even illegal??)

[ibejoeb]

In that context, yes, there are certainly cases where making space is reasonable and legal, like stopping shy of side intersection while (traffic is stopped) to allow a turn.

Stopping or altering traffic isn't, though. You shouldn't stop at a green to allow another driver to maneuver for all the same reasons.